_ Git - rust-lightning/blob - lightning-block-sync/src/rest.rs

   1 //! Simple REST client implementation which implements [`BlockSource`] against a Bitcoin Core REST
   2 //! endpoint.
   3
   4 use crate::{BlockData, BlockHeaderData, BlockSource, AsyncBlockSourceResult};
   5 use crate::http::{BinaryResponse, HttpEndpoint, HttpClient, JsonResponse};
   6 use crate::gossip::UtxoSource;
   7 use crate::convert::GetUtxosResponse;
   8
   9 use bitcoin::OutPoint;
  10 use bitcoin::hash_types::BlockHash;
  11
  12 use std::convert::TryFrom;
  13 use std::convert::TryInto;
  14 use std::sync::Mutex;
  15
  16 /// A simple REST client for requesting resources using HTTP `GET`.
  17 pub struct RestClient {
  18         endpoint: HttpEndpoint,
  19         client: Mutex<Option<HttpClient>>,
  20 }
  21
  22 impl RestClient {
  23         /// Creates a new REST client connected to the given endpoint.
  24         ///
  25         /// The endpoint should contain the REST path component (e.g., http://127.0.0.1:8332/rest).
  26         pub fn new(endpoint: HttpEndpoint) -> std::io::Result<Self> {
  27                 Ok(Self { endpoint, client: Mutex::new(None) })
  28         }
  29
  30         /// Requests a resource encoded in `F` format and interpreted as type `T`.
  31         pub async fn request_resource<F, T>(&self, resource_path: &str) -> std::io::Result<T>
  32         where F: TryFrom<Vec<u8>, Error = std::io::Error> + TryInto<T, Error = std::io::Error> {
  33                 let host = format!("{}:{}", self.endpoint.host(), self.endpoint.port());
  34                 let uri = format!("{}/{}", self.endpoint.path().trim_end_matches("/"), resource_path);
  35                 let mut client = if let Some(client) = self.client.lock().unwrap().take() { client }
  36                         else { HttpClient::connect(&self.endpoint)? };
  37                 let res = client.get::<F>(&uri, &host).await?.try_into();
  38                 *self.client.lock().unwrap() = Some(client);
  39                 res
  40         }
  41 }
  42
  43 impl BlockSource for RestClient {
  44         fn get_header<'a>(&'a self, header_hash: &'a BlockHash, _height: Option<u32>) -> AsyncBlockSourceResult<'a, BlockHeaderData> {
  45                 Box::pin(async move {
  46                         let resource_path = format!("headers/1/{}.json", header_hash.to_string());
  47                         Ok(self.request_resource::<JsonResponse, _>(&resource_path).await?)
  48                 })
  49         }
  50
  51         fn get_block<'a>(&'a self, header_hash: &'a BlockHash) -> AsyncBlockSourceResult<'a, BlockData> {
  52                 Box::pin(async move {
  53                         let resource_path = format!("block/{}.bin", header_hash.to_string());
  54                         Ok(BlockData::FullBlock(self.request_resource::<BinaryResponse, _>(&resource_path).await?))
  55                 })
  56         }
  57
  58         fn get_best_block<'a>(&'a self) -> AsyncBlockSourceResult<'a, (BlockHash, Option<u32>)> {
  59                 Box::pin(async move {
  60                         Ok(self.request_resource::<JsonResponse, _>("chaininfo.json").await?)
  61                 })
  62         }
  63 }
  64
  65 impl UtxoSource for RestClient {
  66         fn get_block_hash_by_height<'a>(&'a self, block_height: u32) -> AsyncBlockSourceResult<'a, BlockHash> {
  67                 Box::pin(async move {
  68                         let resource_path = format!("blockhashbyheight/{}.bin", block_height);
  69                         Ok(self.request_resource::<BinaryResponse, _>(&resource_path).await?)
  70                 })
  71         }
  72
  73         fn is_output_unspent<'a>(&'a self, outpoint: OutPoint) -> AsyncBlockSourceResult<'a, bool> {
  74                 Box::pin(async move {
  75                         let resource_path = format!("getutxos/{}-{}.json", outpoint.txid.to_string(), outpoint.vout);
  76                         let utxo_result =
  77                                 self.request_resource::<JsonResponse, GetUtxosResponse>(&resource_path).await?;
  78                         Ok(utxo_result.hit_bitmap_nonempty)
  79                 })
  80         }
  81 }
  82
  83 #[cfg(test)]
  84 mod tests {
  85         use super::*;
  86         use crate::http::BinaryResponse;
  87         use crate::http::client_tests::{HttpServer, MessageBody};
  88         use bitcoin::hashes::Hash;
  89
  90         /// Parses binary data as a string-encoded `u32`.
  91         impl TryInto<u32> for BinaryResponse {
  92                 type Error = std::io::Error;
  93
  94                 fn try_into(self) -> std::io::Result<u32> {
  95                         match std::str::from_utf8(&self.0) {
  96                                 Err(e) => Err(std::io::Error::new(std::io::ErrorKind::InvalidData, e)),
  97                                 Ok(s) => match u32::from_str_radix(s, 10) {
  98                                         Err(e) => Err(std::io::Error::new(std::io::ErrorKind::InvalidData, e)),
  99                                         Ok(n) => Ok(n),
 100                                 }
 101                         }
 102                 }
 103         }
 104
 105         #[tokio::test]
 106         async fn request_unknown_resource() {
 107                 let server = HttpServer::responding_with_not_found();
 108                 let client = RestClient::new(server.endpoint()).unwrap();
 109
 110                 match client.request_resource::<BinaryResponse, u32>("/").await {
 111                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::Other),
 112                         Ok(_) => panic!("Expected error"),
 113                 }
 114         }
 115
 116         #[tokio::test]
 117         async fn request_malformed_resource() {
 118                 let server = HttpServer::responding_with_ok(MessageBody::Content("foo"));
 119                 let client = RestClient::new(server.endpoint()).unwrap();
 120
 121                 match client.request_resource::<BinaryResponse, u32>("/").await {
 122                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::InvalidData),
 123                         Ok(_) => panic!("Expected error"),
 124                 }
 125         }
 126
 127         #[tokio::test]
 128         async fn request_valid_resource() {
 129                 let server = HttpServer::responding_with_ok(MessageBody::Content(42));
 130                 let client = RestClient::new(server.endpoint()).unwrap();
 131
 132                 match client.request_resource::<BinaryResponse, u32>("/").await {
 133                         Err(e) => panic!("Unexpected error: {:?}", e),
 134                         Ok(n) => assert_eq!(n, 42),
 135                 }
 136         }
 137
 138         #[tokio::test]
 139         async fn parses_negative_getutxos() {
 140                 let server = HttpServer::responding_with_ok(MessageBody::Content(
 141                         // A real response contains a few more fields, but we actually only look at the
 142                         // "bitmap" field, so this should suffice for testing
 143                         "{\"chainHeight\": 1, \"bitmap\":\"0\",\"utxos\":[]}"
 144                 ));
 145                 let client = RestClient::new(server.endpoint()).unwrap();
 146
 147                 let outpoint = OutPoint::new(bitcoin::Txid::from_byte_array([0; 32]), 0);
 148                 let unspent_output = client.is_output_unspent(outpoint).await.unwrap();
 149                 assert_eq!(unspent_output, false);
 150         }
 151
 152         #[tokio::test]
 153         async fn parses_positive_getutxos() {
 154                 let server = HttpServer::responding_with_ok(MessageBody::Content(
 155                         // A real response contains lots more data, but we actually only look at the "bitmap"
 156                         // field, so this should suffice for testing
 157                         "{\"chainHeight\": 1, \"bitmap\":\"1\",\"utxos\":[]}"
 158                 ));
 159                 let client = RestClient::new(server.endpoint()).unwrap();
 160
 161                 let outpoint = OutPoint::new(bitcoin::Txid::from_byte_array([0; 32]), 0);
 162                 let unspent_output = client.is_output_unspent(outpoint).await.unwrap();
 163                 assert_eq!(unspent_output, true);
 164         }
 165 }